Three 4-(4-fluoro-phen-yl)piperazin-1-ium salts containing organic anions: supra-molecular assembly in one, two and three dimensions

Syntheses and crystal structures of 4-(4-nitrophenyl)piperazin-1-ium benzoate monohydrate and 4-(4-nitrophenyl)piperazin-1-ium 2-carboxy-4,6-dinitrophenolate

Two new salts of the 4-(4-nitro­phen­yl)piperazin-1-ium cation have been prepared by co-crystallization with aromatic carb­oxy­lic acids. The supra­molecular assembly in the benzoate salt, which crystallizes as a mono-hydrate, is two dimensional, while that in the 2-carb­oxy-4,6-di­nitro­phenolate salt is three dimensional.

Crystal structures are reported for two mol­ecular salts containing the 4-(4-nitro­phen­yl)piperazin-1-ium cation. Co-crystallization from methanol/ethyl acetate solution of N-(4-nitro­phen­yl)piperazine with benzoic acid gives the benzoate salt, which crystallizes as a monohydrate, C₁₀H₁₄N₃O₂·C₇H₅O₂·H₂O, (I), and similar co-crystallization with 3,5-di­nitro­salicylic acid yields the 2-carb­oxy-4,6-di­nitro­phenolate salt, C₁₀H₁₄N₃O₂·C₇H₃N₂O₇, (II). In the structure of (I), a combination of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds links the components into sheets, while in the structure of (II), the supra­molecular assembly, generated by hydrogen bonds of the same types as in (I), is three dimensional. Comparisons are made with the structures of some related compounds.

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions: supra-molecular assembly in zero, one, two and three dimensions

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions have been prepared and structurally characterized. In the isostructural 4-chloro-benzoate and 4-bromo-benzoate salts, C11H17N2O+·C7H4ClO2 - (I) and C11H17N2O+·C7H4BrO2 - (II), and the 4-iodo-benzoate salt C11H17N2O+·C7H4IO2 - (III), the ions are linked by N-H⋯O hydrogen bonds, forming centrosymmetric R 4 4(12) four-ion aggregates; a similar aggregate is formed in the 2-chloro-benzoate salt (V), isomeric with (I). In the 2-fluoro-benzoate salt C11H17N2O+·C7H4FO2 - (IV), and the isomorphous pair of salts, the 2-bromo-benzoate (VI), isomeric with (II) and 2-iodo-benzoate (VII), isomeric with (III), N-H⋯O and C-H⋯π(arene) interactions link the components into three-dimensional arrays. Four-ion R 4 4(12) aggregates are also found in the 2-methyl-benzoate, 4-amino-benzoate and 4-nitro-benzoate salts, C11H17N2O+·C8H7O2 - (VIII), C11H17N2O+·C7H6NO2 - (IX) and C11H17N2O+·C7H4NO4 - (X), but those in (IX) are linked into complex sheets by an additional N-H⋯O hydrogen bond. In the 3,5-dinitrobenzoate salt, C11H17N2O+·C7H3N2O6 -·2H2O (XI), N-H⋯O and O-H⋯O hydrogen bonds link the components into a complex ribbon structure. In the picrate salt, C11H17N2O+·C6H2N3O7 - (XII), the four-ion aggregates are linked into chains of rings by C-H⋯O hydrogen bonds. In the hydrogen maleate salt, C11H17N2O+·C4H3O4 - (XIII), two- and three-centre hydrogen bonds link the ions into a ribbon structure while both anions contain very short but asymmetric O-H⋯O hydrogen bonds, having O⋯O distances of 2.4447 (16) and 2.4707 (17) Å. O-H⋯O Hydrogen bonds link the anions in the hydrogen fumarate salt (XIV), isomeric with (XIII), into chains that are linked into sheets via N-H⋯O hydrogen bonds. In the hydrogen (2R,3R)-tartrate salt, C11H17N2O+·C4H5O6 -·1.698H2O (XV), the anions are linked into sheets by O-H⋯O hydrogen bonds. Comparisons are made with the structures of some related compounds.

The crystal structures of salts of N-(4-fluoro-phen-yl)piperazine with four aromatic carb-oxy-lic acids and with picric acid

The structures are reported for five salts formed by reactions between N-(4-fluoro-phen-yl)piperazine and aromatic acids. In 4-(4-fluoro-phen-yl)piperazin-1-ium 2-fluoro-benzoate monohydrate, C10H14FN2 +·C7H4FO2 -·H2O, (I), the components are linked by a combination of N-H⋯O and O-H⋯O hydrogen bonds to form a chain of alternating R 4 6(12) and R 6 6(16) rings. The ionic components of 4-(4-fluoro-phen-yl)piperazin-1-ium 2-bromo-benzoate 0.353-hydrate, C10H14FN2 +·C7H4BrO2 -·0.353H2O, (II), are linked by N-H⋯O hydrogen bonds to form a centrosymmetric four-ion aggregate containing an R 4 4(12) motif, and these aggregates are linked into a mol-ecular ladder by a single C-H⋯π(arene) hydrogen bond. 4-(4-Fluoro-phen-yl)piperazin-1-ium 2-iodo-benzoate, C10H14FN2 +·C7H4IO2 -, (III), crystallizes with Z' = 2 in space group P : the four independent ions are linked by N-H⋯O hydrogen bonds to form a non-centrosymmetric aggregate again containing an R 4 4(12) motif, and aggregates of this type are linked into a ribbon by a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds. The anion in 4-(4-fluoro-phen-yl)piperazin-1-ium 2,4,6-tri-nitro-phenolate, C10H14FN2 +·C6H2N3O7 -, (IV), shows clear evidence of extensive electronic delocalization from the phenolate O atom into the adjacent ring. The ions are linked by a combination of two-centre N-H⋯O and three-centre N-H⋯(O)2 hydrogen bonds to form centrosymmetric four-ion aggregates containing three types of ring. The ions in 4-(4-fluoro-phen-yl)piperazin-1-ium 3,5-di-nitro-benzoate, C10H14FN2 +·C7H3N2O6 -, (V), are again linked by N-H⋯O hydrogen bonds to form centrosymmetric R 4 4(12) aggregates, which are themselves linked by a C-H⋯π(arene) hydrogen bond to form sheets, the stacking of which leads to the formation of narrow channels, containing disordered and/or mobile solvent entities. Comparisons are made with some related structures.